Language and cognition in children with metachromatic leukodystrophy: onset and natural course in a nationwide cohort

Table 2 Age and time after onset of language and cognitive decline in late-infantile and juvenile MLD

a) Age [Months]	Late-infantile			Juvenile			p
	P25	Median	P75	P25	Median	P75
Loss of complete sentences	28	30	31	84	132	- - -	<0,0001
Loss of two-word-sentences	30	32	36	90	174	- - -	<0,0001
Loss of single meaningful words	31	32	36	98	- - -	- - -	<0,0001
First language decline	26	30	31	69	98	192	<0,0001
Complete loss of expressive language	28	32	36	87	153	- - -	<0,0001
Problems in concentration	31	- - -	- - -	62	84	113	0,0808
Behavioural problems	28	31	- - -	78	142	192	<0,0001
Decline in reading, writing and calculating	- - -	- - -	- - -	87	128	180	- - -
Loss of any communication	48	51	- - -	192	- - -	- - -	0,0011
b) Time after onset [Months]	Late-infantile			Juvenile			p
	P25	Median	P75	P25	Median	P75
Loss of complete sentences	11	17	19	12	72	- - -	0,0409
Loss of two-word-sentences	12	17	20	38	96	- - -	0,0056
Loss of single meaningful words	11	17	20	43	- - -	- - -	0,0002
First language decline	9	12	16	5	24	72	0,0445
Complete loss of expressive language	12	15	20	16	72	- - -	<0,0001
Problems in concentration	16	- - -	- - -	0	6	14	<0,0001
Behavioural problems	9	18	21	6	32	- - -	0,4415
Decline in reading, writing and calculating	- - -	- - -	- - -	12	48	70	- - -
Loss of any communication	30	33	- - -	- - -	- - -	- - -	0,0332

Parameters of regression of language and cognitive abilities correspond to the parameters introduced in the Methods section. P25 indicates the 25th percentile, median indicates the 50th percentile and P75 indicates the 75th percentile. Age and time after onset are given in months.

ISSN: 1750-1172